ORLANDO, Fla. — Casey Anthony was spending her last hours in jail Saturday night preparing for an uncertain future after nearly three years behind bars.

Orange County Jail officials planned to release Anthony some time Sunday under circumstances they refused to disclose. Experts said she would likely be released in the dead of night, and her defense team will try to keep her away from the glare of the media spotlight.

That could be difficult: More than a dozen television trucks and scores of reporters and cameramen were outside the jail by 11 p.m. Local television stations went live with coverage Saturday night.

Law enforcement officials put up plastic barricades around the jail's booking and release center, and about seven or eight deputies wearing bullet-proof vests patrolled the area. At least one officer carried an assault weapon. About five officers patrolled the area on horseback.

As midnight approached, upward of 100 spectators had gathered outside the jail. The crowd included about a half-dozen, sign-carrying protesters who had gathered there, despite a thunderstorm that brought heavy rain over Orlando.

Barbara Tobin, a semi-retired teacher, drove up from Fort Lauderdale and held a "Justice for Caylee" sign.

"I'm disgusted and feel justice has not been served," she said. "It has really made me feel that there is something wrong with our justice system."

One man, Tim Allen, 24, held the "Casey, will you marry me" sign he carried during her sentencing hearing earlier this month.

"She's beautiful. She has her own unique features," the Orlando pizzeria worker said. "She's pretty and she has a really nice body. That's what young guys like and I'm a young guy.

Earlier, Ronald Brock, 72, was driving around the jail in a red truck decorated with signs equating Anthony with abortion, including one that tells her "Jesus is the final judge."

"Even if nothing happens from our viewpoint, from our thinking, when you take the life of another person something inside you dies," Brock said.

One of her attorneys, Cheney Mason, said Friday that Anthony is scared to leave jail, given numerous threats on her life and the scorn of a large segment of the public that believes she had something to do with the June 2008 death of her 2-year-old daughter, Caylee.

Anthony was acquitted July 5 of first-degree murder in Caylee's death. She was found guilty of four counts of lying to police, but with time served and good behavior credits, she doesn't have to serve out her four-year sentence.

Another defense attorney, Charles Greene, said Friday that Anthony was "emotionally unstable" and needed "a little breathing room" after the draining two-month trial.

That could be difficult, given the vitriol directed at Anthony. After the verdict, anger spilled onto social networks like Facebook and Twitter from people who had spent weeks watching the trial on local and cable television networks. The cable network HLN, featuring former prosecutor and outspoken Anthony critic Nancy Grace, has drawn some of its highest ratings with nonstop coverage of the case.

On Friday, Anthony's legal team said it had received an emailed death threat with a manipulated photo showing their 25-year-old client with a bullet hole in her forehead. It has been forwarded to authorities. Officials had said earlier this week that they had not received any credible threats, but they did not return a phone call about that email.

In Orlando and elsewhere, many remain convinced Anthony isn't totally innocent. David Waechter recorded the trial and watched it at home with his wife every day after work. He said Anthony was guilty of "something, for sure."

"I'm perplexed. You know there is something there, but you don't know what," he said. "Yet she is getting out."

Others who have witnessed Anthony's saga with front-row seats said they were ready for the media attention to die down.

"Most people I talk to, they're done with it," Mandy Williams, a 38-year-old county parks employee, said outside a busy grocery story. "When it came out she was not guilty, people were ticked off."

Steven Klosterman, who owns a property management company, said if Anthony were to stay in Orlando, "I think she'll wind up like her daughter," given the threats she has received.

"Good luck to her," said Klosterman, 43. "She's going to have a hard time."

Security experts have said Anthony will need to hole up inside a safe house protected by bodyguards, perhaps for weeks, in case someone tries to make good on one of those threats. Ideally, several SUVs with tinted windows will pull up to the jail to whisk her away, probably in the middle of the night, experts said. Jail officials have not disclosed when she will be released.

Exactly where she will go also remains unclear. It's unlikely she'll return to the home she once shared with her parents, as the trial left her family fractured. Defense attorney Jose Baez argued during the trial that Caylee accidentally drowned in the family pool and that Casey Anthony's father, George, covered it up to make it look like a homicide. Baez also argued that George Anthony molested his daughter when she was a child – which resulted in psychological issues that caused her to lie and act without apparent remorse after Caylee went missing. George Anthony vehemently denied the allegations, and no witnesses were called to support the claims.

"Most of the time you can always go home, but she doesn't have that option," said Daniel Meachum, an Atlanta lawyer who has represented football star Michael Vick and actor Wesley Snipes. "Baez has to have somewhere for her to go for her to get herself together."

Casey Anthony was convicted of telling detectives several lies in July 2008, when Caylee's disappearance was reported. She said that Caylee had been kidnapped by a nonexistent nanny, among other things.

Caylee's remains were found that December in woods near the Anthony family home.

While defense attorneys argued that Caylee's death was an accident, prosecutors alleged that Anthony suffocated her daughter with duct tape because motherhood interfered with her desire for a carefree life of partying with friends and spending time with her boyfriend. Jurors have told various media outlets that prosecutors didn't prove their case beyond a reasonable doubt as required for a conviction – although some have added that they don't think Anthony is completely innocent.